Melanoma has long represented a unique challenge in oncology. In its early stages, it can often be cured with surgery alone, resulting in excellent survival outcomes. Its biology is complex and heterogeneous, often including mutations such as BRAF and NRAS, which partly explain its high immunogenicity but also its capacity to relapse. For many decades, the standard approach in resectable stage III melanoma was surgery first, followed by adjuvant therapy. In the last decade, the development of immune checkpoint inhibitors created the opportunity to treat patients before surgery. The neoadjuvant approach is based on the hypothesis that treatment of the intact tumor may enhance antitumor immune priming and activation. The first prospective neoadjuvant studies, including OpACIN and OpACIN-neo, showed high pathological response rates with ipilimumab plus nivolumab and introduced pathological response as an early marker of long-term benefit. The PRADO study showed that treatment response could guide the extent of surgery required. The SWOG S1801 trial demonstrated better event-free survival with perioperative pembrolizumab compared to adjuvant therapy alone. Lastly, the phase III NADINA trial showed that neoadjuvant ipilimumab plus nivolumab followed by response-adapted adjuvant therapy significantly improves outcomes. Biomarkers such as PD-L1, IFN-γ signature, tumor mutational burden and imaging (PET scan) appear promising to predict response, but none have been sufficiently validated for routine clinical practice.

The role of adjuvant therapy in stage III melanoma is well established in clinical practice. Because stage IIB–IIC melanoma carries a risk of recurrence and melanoma-specific mortality comparable to that of stage III disease, adjuvant approaches have also been developed for patients with thick stage II tumors. Both pembrolizumab and nivolumab have demonstrated efficacy in reducing the risk of local and distant recurrence in patients with high-risk stage II melanoma, whereas evidence supporting the use of BRAF-MEK inhibitors in this setting remains inconclusive. Combinations of immune checkpoint inhibitors, as well as immunotherapy combined with mRNA-based vaccines, are currently under investigation in clinical trials. However, given the non-trivial risk of immune-related adverse events, careful selection of patients with stage II disease who are most likely to derive meaningful benefit from adjuvant therapy is essential. In this context, several clinicopathologic variables and gene expression profiling-based prognostic tools have been proposed to refine risk stratification. To date, however, none of these instruments have been incorporated into routine clinical practice, and no validated predictive biomarkers are available. Accordingly, optimal patient selection for adjuvant therapy remains an important unmet clinical need in early-stage melanoma.

Melanoma adjuvant therapy has substantially improved recurrence-free and distant metastasis-free survival in patients with resected high-risk disease, and more recently, these advances have extended to earlier stages. However, important unmet needs remain, including the management of stage IIIA disease, the optimal treatment strategy after relapse on adjuvant therapy, and the identification of biomarkers capable of refining patient selection. This review summarizes recent advances and unresolved questions in the adjuvant and neoadjuvant treatment of melanoma. We discuss novel systemic strategies, including immune checkpoint inhibitor combinations and personalized neoantigen mRNA vaccines, together with the expanding role of neoadjuvant approaches. We also examine prognostic and predictive tools—such as clinicopathologic models, circulating tumor DNA, serum biomarkers, tumor microenvironment features, and gene expression profiling—that may help better define recurrence risk and therapeutic benefit. Current evidence suggests that although modern therapies have changed the natural history of resected melanoma, a substantial proportion of patients are still overtreated or undertreated when treatment decisions are based on stage alone. Future progress will depend on integrating biological risk stratification with clinical staging and optimizing treatment sequencing across adjuvant and neoadjuvant settings.

Melanoma adjuvant therapy has substantially improved recurrence-free and distant metastasis-free survival in patients with resected high-risk disease, and more recently these advances have extended to earlier stages. However, important unmet needs remain, including the management of stage IIIA disease, the optimal treatment strategy after relapse on adjuvant therapy, and the identification of biomarkers capable of refining patient selection. This review summarizes recent advances and unresolved questions in the adjuvant and neoadjuvant treatment of melanoma. We discuss novel systemic strategies, including immune checkpoint inhibitor combinations and personalized neoantigen mRNA vaccines, together with the expanding role of neoadjuvant approaches. We also examine prognostic and predictive tools - such as clinicopathologic models, circulating tumor DNA, serum biomarkers, tumor microenvironment features, and gene expression profiling – that may help better define recurrence risk and therapeutic benefit. Current evidence suggests that although modern therapies have changed the natural history of resected melanoma, a substantial proportion of patients are still overtreated or undertreated when treatment decisions are based on stage alone. Future progress will depend on integrating biological risk stratification with clinical staging and on optimizing treatment sequencing across adjuvant and neoadjuvant settings.